A variety of prefabricated polymer building components have been designed for improving the insulation R-factor of exterior walls. Most such building components comprise foamed or plastic materials and involve either foam-core panels or building blocks. Prefabricated foam-core panels typically comprise a solid foam core sandwiched between two layers of rigid materials, including oriented strand board, waferboard, plywood and thin sheet metal. Foamed plastic building blocks typically have hollow passages which form a series of interlocking vertical and horizontal passages in the assembly. The passages may be filled with concrete during assembly. After the concrete solidifies, the foamed blocks may be left in place as insulation.
Various foamed plastic building blocks have been designed for specific applications and to obviate particular problems. U.S. Pat. No. 3,782,049 (Sachs) and U.S. Pat. No. 4,532,745 (Kinard) disclose wall forming blocks made of foamed plastic material, and having vertical openings and upwardly opening channels extending along their upper edges. The blocks are stacked in courses to form a wall, and a concrete slurry is poured or pumped into the openings and channels to form a concrete grid within the wall. Both blocks include attachment means for anchoring cladding materials, but require significant quantities of concrete to assemble. U.S. Pat. No. 4,860,515 (Browning, Jr.) also discloses a self-supporting, self-insulating form for use in construction with concrete. Although this design also provides an improved means for attaching materials to the polymer block, it requires a significant amount of concrete and a number of components, including internal folding metal plates and pivotable wing structures. U.S. Pat. No. 4,823,534 (Hebinck) discloses a method for forming building walls using polystyrene blocks, wherein the blocks comprise vertical voids and horizontal depressions. The voids and depression are filled with concrete to form concrete posts and beams. This design purportedly provides a wall with improved R value but, like the above-described blocks, requires a significant amount of concrete and numerous components, including horizontal and vertical reinforcing rods which must be hooked and intertwined during assembly.
A wide variety of foam wall panels are also available for use with conventional wood frames and concrete. U.S. Pat. No. 4,944,127 (Clear) discloses a composite panel for use with wood frame construction having increased resistance to delamination. The panel comprises a foam layer with inclined grooves and an overlaying concrete layer with integral projections extending into the grooves. U.S. Pat. No. 5,079,885 (Dettbarn), U.S. Pat. No. 5,279,088 (Heydon) and U.S. Pat. No. 5,377,470 (Hebinck) each disclose wall panels or wall panel assemblies comprising wooden posts and rigid foam plastic panels extending between adjacent posts. U.S. Pat. No. 5,216,854 (Emmert) discloses a building system which utilizes laminated panels for the walls and for a self supporting cathedral-type roof. U.S. Pat. No. 5,172,532 (Gibbar, Jr.) discloses a reinforced polymer wall panel having a sculptured grooved surface, preferably including reinforcement rods, and a concrete overlay. The grooves may be shaped as an I-beam for enhanced reinforcement and to strengthen the panels.
Despite the number and variety of products and techniques known for building energy-efficient walls using foam blocks or panels, the use of these materials and techniques has resulted in only moderate success. All known building structures of this type have certain inherent limitations and disadvantages. While certain prior foam products permit the construction of well insulated walls, all require either a large number of components, a wood frame or substantial quantities of cement. Such structures are therefore difficult or expensive to manufacture and/or assemble.
The present invention specifically addresses these and other deficiencies in the prior art and provides an insulated polymer wall panel structure that is economical, simple to manufacture and assemble, termite resistant, employs a minimal number of components, and requires a minimal amount of concrete.